How to convert Excel to CSV for free, in your browser (XLSX to CSV)

How to convert Excel to CSV

Upload the .xlsx file, click "Convert and download" and a .csv with the same name downloads right away. The tool reads the first sheet of the workbook, separates columns with commas, writes the text as UTF-8 and drops colors, formulas and formatting: only the content is left, which is what import systems want. Everything happens in your browser.

1. Open the "Excel (XLSX) to CSV" tool and upload the .xlsx file (you can upload several at once).
2. Make sure the table you want is on the first sheet of the file: that is the one that gets converted.
3. Click "Convert and download". With more than one file, the button reads "Convert 2 spreadsheets", for example.
4. Get the .csv with the same name as the original file (one per spreadsheet uploaded), ready to import.

What the tool does (and what it doesn't)

• It reads only the first sheet. If the table you need is on another sheet, move it to the first position in Excel (or save it as a separate file) before uploading. There is no sheet picker and no warning when other sheets exist.
• Separator: always a comma, the CSV standard. If the destination system requires semicolons, pick the separator on its import screen or open the CSV in a text editor and replace them. A value that contains a comma, quotes or a line break is wrapped in quotes, as the CSV standard requires.
• Encoding: the CSV comes out as UTF-8, the most widely accepted today. Accents, special letters and emoji are preserved.
• Dates: cells that Excel marked as dates come out in the CSV as day/month/year (e.g., 21/07/2021; with a time, 21/07/2021 14:30). A cell that Excel did not mark as a date comes out as stored, which may be Excel's internal number (45658); dates typed as text stay text. Check the column before importing.
• Formulas become their last calculated value; true/false cells come out as TRUE and FALSE; colors, borders, column widths, charts and images are left out.
• It accepts only .xlsx, the modern Excel format. An old .xls must be saved as .xlsx in Excel first. The limit is 2 GB per file.

Why so many systems ask for CSV

CSV stands for "comma-separated values." It is a text file in which each line is a table row and each comma marks the next column, as described in RFC 4180. Any program can read that without depending on Excel, and that simplicity is why an ERP, an online store, a database or an email tool asks for CSV on import: they don't want colors or formulas, they want only the data, row by row, in a predictable way.

Common import errors and how to fix them

• Garbled accents when opening in Excel: the file is fine. Excel on Windows sometimes misreads UTF-8 when you open a CSV with a double click. Use Excel's data import and choose UTF-8, or open the file in Google Sheets or LibreOffice.
• Scrambled columns: the destination expected semicolons and the file uses commas. Adjust the separator on the import screen.
• Wrong header: many systems use the first row as column names. Keep that row clean, with no merged cells and no title rows above the table.
• Leading zero gone (postal codes, product codes): if the value is stored as text in Excel, the zero stays in the CSV; if it is a number with a visual format, the CSV gets the number without the zero. Convert the column to text in Excel first.
• Date turned into a number (e.g., 45658): the cell was not marked as a date in Excel. Apply a date format to the column and convert again, or use the Excel to JSON conversion, which writes dates as yyyy-mm-dd. If the destination expects another format, adjust it on import.

Need JSON, or the opposite direction?

If you want types preserved, the Excel to JSON conversion warns you when the file has other sheets and delivers numbers as numbers, true/false as booleans and dates as yyyy-mm-dd (with a time, yyyy-mm-ddThh:mm). It also has a "One record per line (NDJSON)" option for systems that expect one record per line. That path and the other ones between spreadsheet and JSON are in how to convert CSV, JSON and Excel to each other.

Received a CSV and want a real spreadsheet? The CSV to Excel conversion detects on its own whether the separator is a comma, a semicolon or a tab and produces a one-sheet .xlsx with numbers recognized as numbers. And to query the CSV with SQL, see how to convert CSV or JSON to SQLite.

Everything happens in your browser: the spreadsheet is converted on your own device and is never sent to any server. Your data never leaves your computer.

Before importing, open the CSV in a text editor and look at the date columns and any codes with leading zeros. Those are the two places where the result can differ from what you see in Excel.